It takes only five minutes for the eight preschoolers from Bev Casella's day care to fill a bin half-full of books to check out from the Hennepin County Readmobile parked at the end of her Brooklyn Park driveway.

That's long enough for Casella to get the word that the mobile service is only a sure thing through the end of the year.

"We're operating as usual until we hear from the commissioners," librarians tell her.

For the next half-hour, Casella's tots enthusiastically absorb boos, songs and poems focused on early literacy skills. When they're asked to get up and wiggle their hips during one song, the whole vehicle sways.

But the county's two Readmobiles may be parked in a garage next year under a proposed cut that would save the county's library system $340,000 of the $2 million it needs to balance its budget.

So far it's a cut proposed by library administrators who say they're looking for the most cost-effective ways to continue library service. With five staffers and the cost of fuel, the Read- mobiles are on the block.

It's still a long time until commissioners decide the matter. County Administrator Richard Johnson isn't scheduled to deliver his budget to them until Sept. 23.

The Readmobile cut would have ramifications beyond service to the 80 child-care providers, 60 classrooms and a dozen low-income housing sites they serve. It would cancel part of its birthright.

Mobile book service has been part of Hennepin County Library since bookmobile service began in 1922 as the fledgling county system grew out of the Minneapolis libraries.

By the end of its first year, 92,000 books, or three for every rural resident of the county, had been circulated. Even as the county built libraries in intervening decades, bookmobile service continued into the early 1990s.

As the all-ages bookmobile ended, the youth-oriented Read- mobile was bought in 1991, supplemented by a second vehicle in 2003. Although the target audience is children from birth to age 6, it also serves teen parenting classes and gives parents information on how to prepare their children to read.

Associate librarian Sue Tracy, like other juvenile librarians in the county system, is adept at sneaking pre-literacy skills into stories in a fun way.

She's emphasizing the letter B today and there are books on balls, bubbles, baths, babies and bubble gum, often with rhyming sentences to build phonemic awareness. For preschooler Zach, who's been a big brother for all of two weeks, there's a book called "My Baby and Me."

Bad timing, supporters say

"It's a very valuable service, and I would hate to lose it," Casella said. So would some members of the county library board, judging by last month's board discussion.

Tracy and Rebecca Strauchon, retired supervisor of the Readmobile program, came to last month's board meeting to argue against cutting the program.

"This is a period of time when there's so much research out there about the value of reading to young children," Strauchon said.

Library officials have said that many of the same services still will be available at libraries, but Strauchon and some library board members say low-income suburbanites can't easily get to libraries. Moreover, more children visited the Read- mobile and checked out its materials than were served by some of the county's smallest libraries, according to county statistics.

Some board members suggest keeping at least one Read-mobile running next year. "These children are more likely not to get to the library," said library board member Cynthia Steinke of Bloomington.

Others wondered whether a sponsor would fund part of the vehicles' cost in exchange for some naming rights.

"It would be a pretty easy sell," said board member Roger Hale of Minneapolis.